This invention relates to a storage for large volume waveform data and a data compression technology for the waveform data used for a compact wireless biological information terminal, and the like.
Recently, for medical practices, health management, and the like at hospitals, nursing and care facilities, and households, terminals which wirelessly receive information from biological information sensors (sensors for sensing ECG, pulse, blood pressure, acceleration, and the like) have been developed.
For example, JP 2005-352881A discloses a behavior management system which measures changes in position and posture of respective parts of a body based on sensors attached to the respective parts of the body, and transmits the measured data via a wireless communication device attached to the body.
Moreover, JP 2006-520657A discloses a system in which a medical wireless terminal with a physiological sensor worn on a body measures biological information, and wirelessly transmits the measured data and a gateway device receives the transmitted data and relays the data by the transmission via the Internet to clinical organizations.
Further, Japanese Patent Translation Publication No. 2005-514138 discloses a system in which a medical terminal worn on a body of a patient measures a health state of the user, generates clinical and medical information, and transmits the generated information to a server or the like using a wireless communication, thereby monitoring the patient. Moreover, in the system according to Japanese Patent Translation Publication No. 2005-514138, when the wireless terminal is used out of range, the sensing data is stored in a flash memory compatible with a personal computer (PC), and is collected by the PC.
As a terminal worn on the body for a long period, a compact terminal with low power consumption is needed. Known is a sensor node, which reduces power by an intermittent operation in which the sensor node intermittently starts up, drives a sensor, and wirelessly communicates the result. See, for example, a catalog, “Wireless Sensor Network MOTE-2007”, Crossbow Technology, Inc., retrieved from URL: http://www.xbow.jp/mote2dot.pdf on May 1, 2007. This sensor node can be used to build a wireless network which can extend to a wide area based on relay of data in multiple stages while the network attains low power consumption.